If you prefer Opera 12 over Firefox, Opera is quite simple to install on Ubuntu 12.10 Quantal Quetzal.
First, download and install the .deb package directly from Opera’s website. Opera has superb Linux support, with dedicated packages for fourteen Linux distributions, Ubuntu included (via the Ubuntu *.deb package). You can obtain the package here:
Download the .deb file. Once the .deb file has finished downloading, double-click to install. You’ll be taken to the graphical installer. Click on the Install button to begin the installation of Opera, and then enter your password to authenticate the installation.
Once it’s finished, you can launch Opera by going to the Dash, searching for “opera”, and clicking on the icon for Opera. Note that Opera may crash the first time you launch it – launch it again, and it should stay up the second time.